Christian Post believes his former friend Christian Brueckner came across Madeleine McCann by chance as she slept in her apartment before snatching her.
The 54-year-old is "convinced" the German paedophile took the three-year-old girl in May 2007 at Praia da Luz on the Algarve.
And Mr Post claimed Brueckner boasted of burgling holiday flats during chilling “night-crawls” around the Portuguese resort.